Different snowflake shapes captured by Dr. Kenneth Libbrecht of Caltech.
Courtesy of Kenneth Libbrecht
There are many different types of snow. From the fluffy to the slushy, this slippery frozen stuff comes in all different shapes and sizes.
From a distance, snowflakes may all look the same, but they are not. In fact, there are lots of different shapes of snowflakes — not just those classic shapes you might try to replicate with paper cut-outs.
In this episode, Dr. Ken Libbrecht answers all of our snowflake questions: How are snowflakes made? Why are they different shapes? How is it that they’re all unique? And how does a scientist who lives in southern California study snow? And, he also lets us in on his brush with a couple Arendelle princesses.
Plus our pal Ruby Guthrie pays her local ski slope to visit a snow-making machine called “Kevin.” And of course, there’s a new Mystery Sound to warm your ears.
If you’re looking for some fun snowflake activities to do at home, Ken’s provided this great list — and you don’t need to live in a cold climate for all of them.
Audio Transcript
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PT: You're listening to Brains On.
RUTHIE: Where we're serious about being curious.
CHILD: Brains On is supported in part by a grant from the National Science Foundation.
MENAKA WILHELM: Ruby, I'm about to video call Marc, Sanden, and Molly to see how their road trip is going. You want to join in?
RUBY GUTHRIE: Ooh, here I come. Just grabbing a snack.
MENAKA WILHELM: I know they were planning on using their new vehicle to tunnel into the Earth. I wonder how it's going.
[TYPING]
[CHIMES]
MOLLY BLOOM: Ruby! Menaka! Oh, it's so good to see your faces.
MENAKA WILHELM: You, too, Molly.
RUBY GUTHRIE: Is it raining in there?
MOLLY BLOOM: Raining? Oh, right, because my hair is all wet. Nope, I'm just very sweaty.
SANDEN TOTTEN: Hey, Menaka and Ruby!
MENAKA WILHELM: Hi, Sanden.
RUBY GUTHRIE: Hey.
MOLLY BLOOM: See, he's super sweaty, too.
SANDEN TOTTEN: Yeah, see how I glisten? Sweat really looks good on me. Anyway, we started our journey at the center of the Earth, the core. It was so neat but also so hot.
MOLLY BLOOM: Yeah, and right now, Marc is piloting in our EXPLORER.
SANDEN TOTTEN: Which stands for extremely practical land and ocean rover exploring remote realms, don't you know?
MOLLY BLOOM: I do know. Yeah, so Marc is piloting the EXPLORER through the part inside the planet called the mantle. It's also very hot.
MARC SANCHEZ: The fact that you feel merely very hot and not burnt to a crisp is a testament to the spectacular design of the EXPLORER-er.
[HORN HONKS]
This all-terrain, all-climate, all-planet vehicle I built is able to withstand the intense temperature and extreme pressure inside the Earth.
MOLLY BLOOM: Good point. Shouldn't you be driving?
MARC SANCHEZ: Oh, yeah. Oops! Got to go!
SANDEN TOTTEN: We've seen so many cool things already, and I'm writing it all down for our book, Road Trip Earth, except it's very hard to hold a pencil when you're this sweaty. Ah. Get back here, pencil.
MOLLY BLOOM: OK, my turn to drive. But first, I'm going to go put on more deodorant.
MARC SANCHEZ: And I'm hoping to take a nap. It's so warm and cozy in here. It feels like camping in a fireplace.
MENAKA WILHELM: OK, stay safe. Talk to you soon!
MOLLY BLOOM: See you later.
RUBY GUTHRIE: Bye.
SANDEN TOTTEN: Bye!
MARC SANCHEZ: Bye!
[CHIMES]
MENAKA WILHELM: Phew, just talking to them made me feel sweaty.
RUBY GUTHRIE: Oh, yeah. Me, too. But lucky for us, I just made this.
[SPLAT]
MENAKA WILHELM: Did you just throw a snowball at me?
RUBY GUTHRIE: Yep.
MENAKA WILHELM: Oh, man. It's on. Snowball fight!
[MUSIC PLAYING]
You're listening to Brains On from APM Studios. I'm Menaka Wilhelm, and I have two co-hosts today from London, Ontario, siblings Ruthie and PT. Hi, you two.
PT: Hi.
RUTHIE: Hi!
MOLLY BLOOM: So Ruthie, you wrote in to us with lots of great questions about snow. And I'm guessing that being from Ontario, you have lots of experience with snow?
RUTHIE: Yeah, we love to play in the snow.
PT: I like digging out the snow dunes to make forts.
RUTHIE: Yeah, we love having snowball fights with our little sister, too.
MENAKA WILHELM: What did you say you like digging out of snow?
PT: Snow dunes.
RUTHIE: Like sometimes like the wind just like goes around on the snow, and it makes big like mountain things.
MENAKA WILHELM: Oh my gosh, so big piles of snow. I've never heard of a snow dune because I grew up in a place that didn't have as much snow.
[CHUCKLES]
PT, what's your favorite thing to do in the snow?
PT: I like to make big snowballs for snowmen and stuff.
MENAKA WILHELM: Oh, what's the biggest snowman you've ever made?
PT: It was four balls. Our dad helped with it, and it was like a bit taller than me.
MENAKA WILHELM: Wow. Ruthie, do you have a favorite thing to do in the snow?
RUTHIE: I like building snowmen, too, and I love snowball fights.
MENAKA WILHELM: Mm.
RUTHIE: But I don't like when you get all cold from snowball fights.
MENAKA WILHELM: So if you were describing to somebody who's never played in snow before, what's it like and how do you feel when snow is first falling down? You go first, Ruthie.
RUTHIE: The deepest snow we've ever got is like 2 feet or something, and we have to shovel it all out. But it's really fun because you're the first person to walk on it, and sometimes, you'll see animal tracks in it. And it's just really cool to play in, so you just sink right into the snow.
PT: I like it because it seems like you're exploring a new planet or something. And then sometimes, you find ice or something under the snow, and you can just dig it up and slide on it.
MENAKA WILHELM: Wow, a whole world of snow. And Ruthie, it turns out you are not the only one with questions about snowflakes. Check out what this dynamic duo asked.
LUCY: Hi, my name is Lucy, and I am 6 years old.
SAM: Hi, my name is Sam, and I'm 8 years old. And we're from Colorado. And our question is why--
LUCY AND SAM: --are snowflakes all different shapes?
MOLLY BLOOM: On the ground or in your hand, snowflakes might look all the same, but they're not.
PT: If you look under a microscope, they have all sorts of different shapes.
RUTHIE: And not just those classic star-like shapes you cut out of paper.
MENAKA WILHELM: There are simple prisms, which look like six-sided blocks.
PT: Sheaths which look like sharpened pencils, pointy.
MENAKA WILHELM: And then there are snowflakes that look just like their names sound.
PT: Such as plates, columns, needles, and stars.
RUTHIE: And there are lots of other shapes, too. So how is that possible? Why are they all different shapes?
MOLLY BLOOM: To find the answer, we talked to Ken Libbrecht, a physicist from Caltech. He's an expert on snowflakes.
RUTHIE: In fact, he understands them so well--
KEN LIBBRECHT: That I was the snowflake consultant on Frozen.
[MUSIC - IDINA MENZEL, "LET IT GO"]
IDINA MENZEL: (SINGING) My soul is spiraling in frozen fractals all around.
KEN LIBBRECHT: For example, one common fractal form is when you have branches, and side branches, and more side branches. And snowflakes are a little like that. They knew there'd be a lot of snowflakes in the movie, and they wanted to make sure they got them right. And so I went over to Disney Studios, and I showed them a lot of pictures of snowflakes. And I guess I convinced them, at least, that to make them all six-sided, which not everyone does, and then they did. So I was pleased with that.
PT: In order to understand how a snowflake gets its shape, you have to look how it first forms way up in the atmosphere.
KEN LIBBRECHT: Clouds are made of mostly water droplets, even when it's below freezing. There's a lot of things that can happen up in the sky, and they all do it some time or another. For example, the water droplets can combine to form raindrops, which are big, and they're big enough to fall. And then the raindrops can freeze on the way down. And those are called sleet particles, and they're not at all like snowflakes. They look like frozen drops of water, which is what they are.
PT: Sleet is not very fun to play in.
KEN LIBBRECHT: And another thing that can happen is you can get the droplets that will hit a snowflake, and they will look like a bunch of droplets stuck together and frozen. That's called graupel. They're soft hail.
RUTHIE: Also, not that fun to play in.
MENAKA WILHELM: So how about snowflakes? They form slowly up in the clouds, starting with a single frozen droplet.
RUTHIE: That single frozen water droplet then absorbs water vapor.
PT: Water vapor is water that's now in the form of gas.
KEN LIBBRECHT: And it ends up about 100,000 water droplets evaporate in the process of making one snowflake.
PT: Whoa, that's a lot of water droplets for one tiny snowflake.
RUTHIE: And really, they're not just snowflakes. They're snow crystals.
CRYSTAL CLEAR APP: That's a crystal.
MENAKA WILHELM: Crystals are special materials where the molecules line up in a nice orderly fashion.
PT: OK, I think I need to pause for a second. There's a lot more that goes into making a snowflake than I anticipated.
MENAKA WILHELM: Yeah, I think we may need the Zoom Ray for a second.
PT: Got it!
MENAKA WILHELM: And a water droplet.
[GULPS]
PT: Ah. Oops, I finished the water.
MENAKA WILHELM: Oh, that's OK. There's still a few drops in the bottom, and that's all we need. Zoom Ray on.
ZOOM RAY: Zoom zoom.
MENAKA WILHELM: Let's zoom way in on this water droplet.
[ZOOMING]
PT: Whoa.
RUTHIE: We've zoomed in so far. I can see the atoms.
MENAKA WILHELM: Yeah, those are the tiny building blocks that make up everything. Everything around you is made of atoms. You are made of atoms. Your clothes are made of atoms. Water is made of atoms. So each atom is like an individual LEGO brick, and just like there are different kinds of LEGO bricks, there are different kinds of atoms, too. And water is made of two different kinds of atoms, hydrogen and oxygen. Let's zoom out just a tidge.
ZOOM RAY: Zoom.
MENAKA WILHELM: OK, now, these are water molecules, and molecules are groups of atoms that are stuck together.
PT: Like how a few LEGO bricks can stick together to make a bigger shape.
MENAKA WILHELM: You got it.
RUTHIE: Ooh, yeah. I can see that each water molecule is made of two hydrogen atoms and one oxygen atom.
PT: Two Hs and one O, H2O. I get it.
MENAKA WILHELM: So whether water is in a liquid, gas, or solid form, it's made of these molecules. And when water is liquid, the molecules are all close together, and they're basically, constantly high fiving each other.
MOLECULES: High five. You're the best. Oh yeah. Way to go, H2O!
MENAKA WILHELM: When liquid water evaporates, individual water molecules break off and float in the air.
MOLECULES: Woohoo! Catch you later, molecule friends.
MENAKA WILHELM: So imagine a water molecule up in the cloud--
WATER MOLECULE: Wee! I'm vapor!
MENAKA WILHELM: --and it bumps into a frozen water droplet.
WATER MOLECULE: This looks like fun! What are you frozen molecule friends up to?
FROZEN MOLECULES: We're holding hands and staying still.
WATER MOLECULE: Fun! Can I join you?
FROZEN MOLECULES: Yes, of course. Let's make a crystal!
[FREEZING]
CRYSTAL CLEAR APP: That's a crystal.
MENAKA WILHELM: So as more water vapor is collected by the frozen water droplet, a snow crystal starts to form. Let's zoom out further and look at our snow crystals.
ZOOM RAY: Zoom, zoom, zoom, zoom.
MENAKA WILHELM: These snow crystals form a very particular shape. The way they like to stick together is in hexagons.
PT: That's a six-sided shape.
RUTHIE: The same shape Ken wanted to make sure the Disney animators got right in Frozen.
MENAKA WILHELM: Different molecules form different kinds of crystals. Salt molecules, for example, like to form cubes.
PT: But water molecules love six-sided hexagons.
MENAKA WILHELM: And these hexagon shapes can branch at the edges to make star shapes. Some are long and skinny and look like needles or columns, and others are flat like plates. So you start with molecules forming hexagon crystals, but they can stick together and form lots of different variations off of that basic shape. OK, time to zoom out and get back to that original question.
[ZOOMING]
PT AND RUTHIE: Why are snowflakes all different shapes?
KEN LIBBRECHT: We don't actually even understand that exactly yet. If you want really nice, stellar snowflakes, the kind that always sort of cut out of paper, those tend to form only when the temperature is around minus 15 Celsius. Columns like needles, the things grow at minus 5. So temperature plays a big role.
The humidity also affects things. The higher the humidity, the faster the crystals grow. And just the nature of the cloud, and whether there are a lot of droplets in the cloud, and then the density of droplets and whether the crystals form low to the ground or way up high in the atmosphere, it all affects the way they look when they fall on your sleeve.
MENAKA WILHELM: Even though we don't totally understand all the reasons that snowflakes take on these different shapes, we do understand the answer to the next question a little better. It was sent to us by Oliver who lives in Thailand.
OLIVER: Hi, I'm Oliver, and I want to know why two snowflakes are never the same.
MENAKA WILHELM: Ken will share the answer with us in just a bit. But first, we must interrupt this very important snowflake discussion for the--
[MUSIC PLAYING]
CHILD: (WHISPERS) Mystery sound.
MENAKA WILHELM: Here it is.
[MYSTERY SOUND]
PT: It sounds like something falling like a bunch of rice.
MENAKA WILHELM: Mm. That's a good guess. And what did you hear, Ruthie?
RUTHIE: I think it sounds like something falling, and I'm trying to think of how it would be like snow. Like maybe it's like someone's like shoveling snow?
MENAKA WILHELM: Oh, I like that guess. I think thinking about things close to snow is-- you're on the right track. Should we listen to it one more time? It's a pretty short sound.
RUTHIE: Yeah.
PT: OK.
[MYSTERY SOUND]
MENAKA WILHELM: All right, Ruthie, did you hear anything new that time?
RUTHIE: Oh, I heard some like leaves. And I'm not sure if they're leaves, but it just sounded sort of like leaves.
MENAKA WILHELM: Mm.
RUTHIE: But I still don't think it's like shoveling snow.
PT: It sounds like to me, like it's digging out something. So maybe like a crusty bit of dirt, or something, or like snow?
MENAKA WILHELM: I think those are great guesses, and we'll be back with the answer after the credits at the end of the show.
[MUSIC PLAYING]
We're working on an episode all about worms, and we want to hear from you. So Ruthie, if you had a pet worm, what would you name it?
RUTHIE: If I had a pet worm, I would name it Wiggles because worms like to wiggle around in the middle of dirt.
MENAKA WILHELM: And how about you, PT?
PT: If I had a pet worm, I'd name it Isaac Newton.
RUTHIE: Why would you name it Isaac Newton?
PT: Because worms like to hang out in apples, and Isaac Newton's famous because an apple fell on his head.
[LAUGHS]
MENAKA WILHELM: I love that answer, and you can send us your answer by heading to brainson.org/contact. While you're there, you can also send us your drawings, mystery sounds, and questions like this one.
CHRISTIAN: My name is Christian from Saint Louis, Missouri. My question is, how do trees make rings inside, and do the rings really show the trees age?
MENAKA WILHELM: You can hear an answer to that question by listening to the Moment of Um podcast. That's our new bite-sized daily podcast. You can find it wherever you listen to Brains On.
PT: Just search for Moment of Um.
MENAKA WILHELM: And if you're looking for a way to support Brains On, it would mean a lot to us if you would preorder our book. Marc, Molly, and Sanden are sharing their adventures in the Explorerer in the new Brains On book, Road Trip Earth. It's full of comics, photos, and cool facts about our favorite planet Earth.
RUTHIE: You can also preorder the very first Brains On picture book.
PT: It's called Earth Friend Forever.
MENAKA WILHELM: You can preorder them by heading to brainson.org/books.
RUTHIE: Thank you.
PT: And keep listening.
RUTHIE: You're listening to Brains On from APM Studios. I'm Ruthie.
PT: I'm PT.
MENAKA WILHELM: And I'm Menaka. Now, back to this question from Oliver.
OLIVER: I want to know why two snowflakes are never the same.
RUTHIE: Snow expert Ken Libbrecht has an answer.
KEN LIBBRECHT: Well, you start with this little, tiny droplet of ice, and there's a lot of factors that are going into it. When they grow in the clouds, the way they look depends on the path they take through the clouds. So since no two snowflakes follow exactly the same path, no two snowflakes really look exactly alike.
MENAKA WILHELM: The paths are individual and a lot depends on the conditions, too. So temperature, humidity, things like that.
RUTHIE: So as the snowflake moves around, bumping into the water molecules, the shape changes. The crystals form, making a complicated looking and delicate structure.
PT: We have a link to Ken's research in the show notes so you can see the gorgeous photos of snowflakes he's captured.
MENAKA WILHELM: Ken is based in Southern California where it doesn't really snow, so he makes his own snowflakes in the lab. And here's how he does it.
KEN LIBBRECHT: Get a freezer, something cold, and just some water. And I'll heat the water up, and water vapor will come off and then cool down the water vapor. And it automatically starts to grow with ice. And so it's really just a question of controlling that process.
MENAKA WILHELM: If you head to our website, you can get ideas for some cool snowflake related activities you can do even if you don't live in a cold climate. You can preserve snowflakes in glue, make ice spikes in your freezer, or cut some scientifically accurate paper snowflakes. Find the link at our website brainson.org.
ROBOT: Brains, brains, brains on.
MENAKA WILHELM: So Ruthie, you also had some questions about how we make snow. Isn't that right?
RUTHIE: Yes, I wanted to know if you can make snow in hot places like near the equator.
MENAKA WILHELM: That's a great question. And we asked our pal, Ruby Guthrie, to look into this for us.
RUBY GUTHRIE: Hey. Yeah, so turns out, we can make our own snow, even in large amounts with the help of some special equipment. It's called artificial snow. And it turns out in order to make this snow, you need cold air. So it's possible you can make snow up on a mountain near the equator if it were chilly willy. But it wouldn't be cold enough in most places.
RUTHIE: Oh, so I won't be able to have a snowball fight on a tropical beach.
RUBY GUTHRIE: Unfortunately, no. But a sandball fight could be kind of fun. Anyways, your question really got me interested in human made snow. So I visited a place that makes snow here in Minnesota.
MENAKA WILHELM: Wait, Ruby, I'm confused. It's winter, and Minnesota is very cold. Isn't there already a ton of snow there?
RUBY GUTHRIE: Yes, Menaka, you are correct. I do live in Minnesota, and I have to shovel a lot.
RUTHIE: Minnesota, more like Minne-snow-ta. Am I right?
RUBY GUTHRIE: Oh, that was punderful, Ruthie. But yes, you heard right. Even here in Minnesnowta, people still make artificial snow. I wanted to see for myself. So I bundled up and visited my local ski hill.
DAMON JOHNSON: Hello, I'm Damon Johnson. I'm the Maintenance Supervisor here at Hyland Hills Ski Area.
MENAKA WILHELM: Damon is one of the many people who helps make snow here. They're called snow makers. And like most ski hills, Hyland relies on artificial snow for all of their activities.
DAMON JOHNSON: So across this entire hill, we have approximately four feet of snow on average. We have to make all the snow that's out here. We can't really depend on mother nature.
MENAKA WILHELM: Right because sometimes, it doesn't snow, and the ski hill gets dry. Or there's already some natural snow, but not enough to coat the hills for skiing, especially after they use machines like snow plows to even everything out. Now, the artificial snow that Damon makes is a little bit different than the natural snow we're very familiar with.
DAMON JOHNSON: The snow that we make is a little bit different than the snow that comes from the sky. The snow that comes from the sky is more of a flatter flake. It compacts. Here, you get a foot of snow naturally occurring. By the time we would run our machines and equipment through it, you'd probably only end up with a couple of inches of snow. So we rely on our snow makers to do the majority of the snow making here.
RUBY GUTHRIE: That sounds so cool. So how do the snow makers do it? I'm picturing like a giant machine that catapults snowmen into the hills.
[CATAPULT CHAINS]
[PLOPS]
PT: Oh, or a laser ray, but instead of lasers, it's snowflakes.
[LASER RAY SHOT]
RUBY GUTHRIE: Whoa, OK, those sound totally awesome. But that's not quite it. Although, I will say the real machines do remind me of something out of a sci-fi movie, they're called snow cannons or snow guns. Picture this, a big barrel propped up on wheels, about 8 feet tall. One end has a giant fan. And the other end is lined with a halo of tiny nozzles just like the ones on a garden hose. It kind of looks like a jet engine. And turns out, it totally sounds like one, too.
[MACHINE WHIRRING]
Yeah, so that's the sound of a snow gun. And this one is named Kevin to be exact.
RUTHIE: Wait, the snow machine is named Kevin?
RUBY GUTHRIE: Yeah, Kevin the Snow Maker.
MENAKA WILHELM: So how does Kevin work?
RUBY GUTHRIE: Well, you can think of Kevin like a sprinkler on a giant fan, basically, just spraying water high up into the air.
DAMON JOHNSON: The water molecule goes into the air. It kind of freezes. There's like a shell around it almost like an egg, and then you want to get that egg to be frozen by the time it hits the ground.
RUBY GUTHRIE: And these water droplets freeze from the outside in, which creates these little rounded balls of ice, which is a bit different than the natural flakes we talked about earlier. But this artificial snow is actually much better for skiing and snowboarding. It's more compact, which makes it easier to smooth out and groom over the hills. Plus, it melts slower.
PT: So when's the best time to make snow?
DAMON JOHNSON: The best time to make snow is when the air is cold and dry.
RUBY GUTHRIE: And since the air is typically coolest at night, that's when the snow makers get down to business.
[MUSIC PLAYING]
So first, it starts with water. Damon pumps water from a nearby pond, and it's really important that that water is nice and cold. That way, it can freeze faster when it hits the air. But the water needs to be broken up into smaller particles. The solution? Mixing the water with a bit of compressed air. That's when lots of air is stuffed into a small space and builds up pressure, just like in a can of hairspray.
DAMON JOHNSON: It forces the water in the air together and atomizes it into smaller particles and then throws it into the air. And then when it's in the air, we throw it up as high up as we can get it to go, gives it a longer chance to freeze. And then it falls down and lands on the ground.
RUBY GUTHRIE: So the mix of water and pressurized air comes shooting out of the nozzles, and that's when the fan blows everything high, high up. And the higher, the better because the water particles will have a longer chance to freeze as they fall to the ground. What does it look like when you have them all going at once?
DAMON JOHNSON: It's kind of neat. It basically is a big like a snow plume that flies up into the air. When it lands on the ground and starts forming onto the ground, we call those whales because it kind of looks like a whale coming out of the ocean.
RUBY GUTHRIE: That's cool, snow whales, pretty awesome. And then they'll take small snow plows and even out those whales into nice smooth hills, perfect for skiing and snowboarding. And snow whales aside, this can be a tough job. You have to be ready for anything, changes in the wind, machines freezing over, or even water lines breaking. And that can get really messy.
DAMON JOHNSON: And sometimes, if it's really cold after you would get hit with the water, it'll freeze to you instantly. And so you end up being like-- the guys will have jackets that are basically a turtle shell of ice, and when you go inside for break, you just take the jacket off and leave it outside. And then when you go back outside, you put it back on because you already have this protective layer.
RUBY GUTHRIE: Right, it's like armor almost at that point.
DAMON JOHNSON: Yep.
RUBY GUTHRIE: This might be challenging work, but ski hills all over the world from Minnesota to the Winter Olympics really depend on this artificial snow.
MENAKA WILHELM: Thanks for visiting, Ruby.
RUBY GUTHRIE: Any time. Now, I'm off to have a snowball fight with Gungador. This should be good.
RUTHIE: Bye, Ruby.
PT: Bye, hope you don't get crushed.
RUBY GUTHRIE: I'll try my best!
[MUSIC PLAYING]
PT: Snowflakes start as frozen water droplets.
RUTHIE: It collects water vapor up in the clouds, which forms an ice crystal.
PT: Each snowflake is different because they're shaped by the different paths they take.
RUTHIE: It is possible to make artificial snow, but the flakes aren't snow crystals. And you still need cold air.
MENAKA WILHELM: That's it for this episode of Brains On.
RUTHIE: It was produced by Molly Bloom, Ruby Guthrie, Marc Sanchez, Sanden Totten, and Menaka Wilhelm.
MENAKA WILHELM: Our fellow is Anna Goldfield, and our Executive Producer is Beth Pearlman. The executives in charge of APM Studios are Joanne Griffith and Alex Schaffert. Special thanks to Tom Nicely, Luke Davies, and Jessie Litton.
PT: Brains On is a nonprofit public radio program.
MENAKA WILHELM: There are lots of ways you can support the show. You can donate, buy our books, or tell your friends about us.
RUTHIE: Head to brainson.org to find the links, to donate, and to preorder the books.
[MUSIC PLAYING]
MENAKA WILHELM: Now, before we go, let's go back to that mystery sound. Here it is.
[MYSTERY SOUND]
All right, so Ruthie, what's your guess this time?
RUTHIE: So my guess before was someone shoveling snow with maybe leaves in it, and now, I'm hearing something like skiing if somebody is like skiing or getting skis on.
PT: It sounds like snow's like flying through the air. So it could be like a cannon blasting out snow or somebody throwing a snowball.
MENAKA WILHELM: Wow, you guys are right on. Are you ready for the answer?
PT: OK.
RUTHIE: Yes, I'm so ready.
MENAKA WILHELM: So this chilly sound was sent in by Elena from Corbin, Kentucky. And it's what you might hear if you jump on a trampoline full of snow. So PT, you had the snow flying through the air, and Ruthie, you had the sort of like feet crunching through snow part.
RUTHIE: Mm.
PT: Oh, cool.
MENAKA WILHELM: You guys just needed to put your answers together.
RUTHIE: Yeah, I've actually jumped on my friend's trampoline with snow on it, so I should have been able to guess that answer.
PT: I haven't gone on a trampoline with snow, but I've gone on it with water. Sounds like a giant drum.
MENAKA WILHELM: Mm, I've only ever jumped on a trampoline in dry conditions. But Ruthie, when you jumped on a trampoline with snow on it, what did it feel like?
RUTHIE: Well, it felt really weird because the trampoline got slippery, and it was like crunchy because it's sort of like all the snow got balls. And it was just coming down, too. So it felt like it was like an echo of us jumping on it. I was jumping on it, and the snow came down after. So it's really cool.
MENAKA WILHELM: Yeah, so great guesses. You guys both did really great listening there.
PT: Thanks.
MENAKA WILHELM: If you have a mystery sound you want to share with us, you can do that at brainson.org/contact. Everyone who sends a question, an idea, a mystery sound, a drawing, or a high five gets added to the Brains Honor Roll. And here's the most recent group of listeners to be added.
[MUSIC PLAYING]
[LISTING HONOR ROLL]
ROBOTS: (SINGING) Brains Honor Roll, high five.
RUTHIE: We'll be back soon with more answers to your questions.
PT: Thanks for listening!
RUTHIE: Where we're serious about being curious.
CHILD: Brains On is supported in part by a grant from the National Science Foundation.
MENAKA WILHELM: Ruby, I'm about to video call Marc, Sanden, and Molly to see how their road trip is going. You want to join in?
RUBY GUTHRIE: Ooh, here I come. Just grabbing a snack.
MENAKA WILHELM: I know they were planning on using their new vehicle to tunnel into the Earth. I wonder how it's going.
[TYPING]
[CHIMES]
MOLLY BLOOM: Ruby! Menaka! Oh, it's so good to see your faces.
MENAKA WILHELM: You, too, Molly.
RUBY GUTHRIE: Is it raining in there?
MOLLY BLOOM: Raining? Oh, right, because my hair is all wet. Nope, I'm just very sweaty.
SANDEN TOTTEN: Hey, Menaka and Ruby!
MENAKA WILHELM: Hi, Sanden.
RUBY GUTHRIE: Hey.
MOLLY BLOOM: See, he's super sweaty, too.
SANDEN TOTTEN: Yeah, see how I glisten? Sweat really looks good on me. Anyway, we started our journey at the center of the Earth, the core. It was so neat but also so hot.
MOLLY BLOOM: Yeah, and right now, Marc is piloting in our EXPLORER.
SANDEN TOTTEN: Which stands for extremely practical land and ocean rover exploring remote realms, don't you know?
MOLLY BLOOM: I do know. Yeah, so Marc is piloting the EXPLORER through the part inside the planet called the mantle. It's also very hot.
MARC SANCHEZ: The fact that you feel merely very hot and not burnt to a crisp is a testament to the spectacular design of the EXPLORER-er.
[HORN HONKS]
This all-terrain, all-climate, all-planet vehicle I built is able to withstand the intense temperature and extreme pressure inside the Earth.
MOLLY BLOOM: Good point. Shouldn't you be driving?
MARC SANCHEZ: Oh, yeah. Oops! Got to go!
SANDEN TOTTEN: We've seen so many cool things already, and I'm writing it all down for our book, Road Trip Earth, except it's very hard to hold a pencil when you're this sweaty. Ah. Get back here, pencil.
MOLLY BLOOM: OK, my turn to drive. But first, I'm going to go put on more deodorant.
MARC SANCHEZ: And I'm hoping to take a nap. It's so warm and cozy in here. It feels like camping in a fireplace.
MENAKA WILHELM: OK, stay safe. Talk to you soon!
MOLLY BLOOM: See you later.
RUBY GUTHRIE: Bye.
SANDEN TOTTEN: Bye!
MARC SANCHEZ: Bye!
[CHIMES]
MENAKA WILHELM: Phew, just talking to them made me feel sweaty.
RUBY GUTHRIE: Oh, yeah. Me, too. But lucky for us, I just made this.
[SPLAT]
MENAKA WILHELM: Did you just throw a snowball at me?
RUBY GUTHRIE: Yep.
MENAKA WILHELM: Oh, man. It's on. Snowball fight!
[MUSIC PLAYING]
You're listening to Brains On from APM Studios. I'm Menaka Wilhelm, and I have two co-hosts today from London, Ontario, siblings Ruthie and PT. Hi, you two.
PT: Hi.
RUTHIE: Hi!
MOLLY BLOOM: So Ruthie, you wrote in to us with lots of great questions about snow. And I'm guessing that being from Ontario, you have lots of experience with snow?
RUTHIE: Yeah, we love to play in the snow.
PT: I like digging out the snow dunes to make forts.
RUTHIE: Yeah, we love having snowball fights with our little sister, too.
MENAKA WILHELM: What did you say you like digging out of snow?
PT: Snow dunes.
RUTHIE: Like sometimes like the wind just like goes around on the snow, and it makes big like mountain things.
MENAKA WILHELM: Oh my gosh, so big piles of snow. I've never heard of a snow dune because I grew up in a place that didn't have as much snow.
[CHUCKLES]
PT, what's your favorite thing to do in the snow?
PT: I like to make big snowballs for snowmen and stuff.
MENAKA WILHELM: Oh, what's the biggest snowman you've ever made?
PT: It was four balls. Our dad helped with it, and it was like a bit taller than me.
MENAKA WILHELM: Wow. Ruthie, do you have a favorite thing to do in the snow?
RUTHIE: I like building snowmen, too, and I love snowball fights.
MENAKA WILHELM: Mm.
RUTHIE: But I don't like when you get all cold from snowball fights.
MENAKA WILHELM: So if you were describing to somebody who's never played in snow before, what's it like and how do you feel when snow is first falling down? You go first, Ruthie.
RUTHIE: The deepest snow we've ever got is like 2 feet or something, and we have to shovel it all out. But it's really fun because you're the first person to walk on it, and sometimes, you'll see animal tracks in it. And it's just really cool to play in, so you just sink right into the snow.
PT: I like it because it seems like you're exploring a new planet or something. And then sometimes, you find ice or something under the snow, and you can just dig it up and slide on it.
MENAKA WILHELM: Wow, a whole world of snow. And Ruthie, it turns out you are not the only one with questions about snowflakes. Check out what this dynamic duo asked.
LUCY: Hi, my name is Lucy, and I am 6 years old.
SAM: Hi, my name is Sam, and I'm 8 years old. And we're from Colorado. And our question is why--
LUCY AND SAM: --are snowflakes all different shapes?
MOLLY BLOOM: On the ground or in your hand, snowflakes might look all the same, but they're not.
PT: If you look under a microscope, they have all sorts of different shapes.
RUTHIE: And not just those classic star-like shapes you cut out of paper.
MENAKA WILHELM: There are simple prisms, which look like six-sided blocks.
PT: Sheaths which look like sharpened pencils, pointy.
MENAKA WILHELM: And then there are snowflakes that look just like their names sound.
PT: Such as plates, columns, needles, and stars.
RUTHIE: And there are lots of other shapes, too. So how is that possible? Why are they all different shapes?
MOLLY BLOOM: To find the answer, we talked to Ken Libbrecht, a physicist from Caltech. He's an expert on snowflakes.
RUTHIE: In fact, he understands them so well--
KEN LIBBRECHT: That I was the snowflake consultant on Frozen.
[MUSIC - IDINA MENZEL, "LET IT GO"]
IDINA MENZEL: (SINGING) My soul is spiraling in frozen fractals all around.
KEN LIBBRECHT: For example, one common fractal form is when you have branches, and side branches, and more side branches. And snowflakes are a little like that. They knew there'd be a lot of snowflakes in the movie, and they wanted to make sure they got them right. And so I went over to Disney Studios, and I showed them a lot of pictures of snowflakes. And I guess I convinced them, at least, that to make them all six-sided, which not everyone does, and then they did. So I was pleased with that.
PT: In order to understand how a snowflake gets its shape, you have to look how it first forms way up in the atmosphere.
KEN LIBBRECHT: Clouds are made of mostly water droplets, even when it's below freezing. There's a lot of things that can happen up in the sky, and they all do it some time or another. For example, the water droplets can combine to form raindrops, which are big, and they're big enough to fall. And then the raindrops can freeze on the way down. And those are called sleet particles, and they're not at all like snowflakes. They look like frozen drops of water, which is what they are.
PT: Sleet is not very fun to play in.
KEN LIBBRECHT: And another thing that can happen is you can get the droplets that will hit a snowflake, and they will look like a bunch of droplets stuck together and frozen. That's called graupel. They're soft hail.
RUTHIE: Also, not that fun to play in.
MENAKA WILHELM: So how about snowflakes? They form slowly up in the clouds, starting with a single frozen droplet.
RUTHIE: That single frozen water droplet then absorbs water vapor.
PT: Water vapor is water that's now in the form of gas.
KEN LIBBRECHT: And it ends up about 100,000 water droplets evaporate in the process of making one snowflake.
PT: Whoa, that's a lot of water droplets for one tiny snowflake.
RUTHIE: And really, they're not just snowflakes. They're snow crystals.
CRYSTAL CLEAR APP: That's a crystal.
MENAKA WILHELM: Crystals are special materials where the molecules line up in a nice orderly fashion.
PT: OK, I think I need to pause for a second. There's a lot more that goes into making a snowflake than I anticipated.
MENAKA WILHELM: Yeah, I think we may need the Zoom Ray for a second.
PT: Got it!
MENAKA WILHELM: And a water droplet.
[GULPS]
PT: Ah. Oops, I finished the water.
MENAKA WILHELM: Oh, that's OK. There's still a few drops in the bottom, and that's all we need. Zoom Ray on.
ZOOM RAY: Zoom zoom.
MENAKA WILHELM: Let's zoom way in on this water droplet.
[ZOOMING]
PT: Whoa.
RUTHIE: We've zoomed in so far. I can see the atoms.
MENAKA WILHELM: Yeah, those are the tiny building blocks that make up everything. Everything around you is made of atoms. You are made of atoms. Your clothes are made of atoms. Water is made of atoms. So each atom is like an individual LEGO brick, and just like there are different kinds of LEGO bricks, there are different kinds of atoms, too. And water is made of two different kinds of atoms, hydrogen and oxygen. Let's zoom out just a tidge.
ZOOM RAY: Zoom.
MENAKA WILHELM: OK, now, these are water molecules, and molecules are groups of atoms that are stuck together.
PT: Like how a few LEGO bricks can stick together to make a bigger shape.
MENAKA WILHELM: You got it.
RUTHIE: Ooh, yeah. I can see that each water molecule is made of two hydrogen atoms and one oxygen atom.
PT: Two Hs and one O, H2O. I get it.
MENAKA WILHELM: So whether water is in a liquid, gas, or solid form, it's made of these molecules. And when water is liquid, the molecules are all close together, and they're basically, constantly high fiving each other.
MOLECULES: High five. You're the best. Oh yeah. Way to go, H2O!
MENAKA WILHELM: When liquid water evaporates, individual water molecules break off and float in the air.
MOLECULES: Woohoo! Catch you later, molecule friends.
MENAKA WILHELM: So imagine a water molecule up in the cloud--
WATER MOLECULE: Wee! I'm vapor!
MENAKA WILHELM: --and it bumps into a frozen water droplet.
WATER MOLECULE: This looks like fun! What are you frozen molecule friends up to?
FROZEN MOLECULES: We're holding hands and staying still.
WATER MOLECULE: Fun! Can I join you?
FROZEN MOLECULES: Yes, of course. Let's make a crystal!
[FREEZING]
CRYSTAL CLEAR APP: That's a crystal.
MENAKA WILHELM: So as more water vapor is collected by the frozen water droplet, a snow crystal starts to form. Let's zoom out further and look at our snow crystals.
ZOOM RAY: Zoom, zoom, zoom, zoom.
MENAKA WILHELM: These snow crystals form a very particular shape. The way they like to stick together is in hexagons.
PT: That's a six-sided shape.
RUTHIE: The same shape Ken wanted to make sure the Disney animators got right in Frozen.
MENAKA WILHELM: Different molecules form different kinds of crystals. Salt molecules, for example, like to form cubes.
PT: But water molecules love six-sided hexagons.
MENAKA WILHELM: And these hexagon shapes can branch at the edges to make star shapes. Some are long and skinny and look like needles or columns, and others are flat like plates. So you start with molecules forming hexagon crystals, but they can stick together and form lots of different variations off of that basic shape. OK, time to zoom out and get back to that original question.
[ZOOMING]
PT AND RUTHIE: Why are snowflakes all different shapes?
KEN LIBBRECHT: We don't actually even understand that exactly yet. If you want really nice, stellar snowflakes, the kind that always sort of cut out of paper, those tend to form only when the temperature is around minus 15 Celsius. Columns like needles, the things grow at minus 5. So temperature plays a big role.
The humidity also affects things. The higher the humidity, the faster the crystals grow. And just the nature of the cloud, and whether there are a lot of droplets in the cloud, and then the density of droplets and whether the crystals form low to the ground or way up high in the atmosphere, it all affects the way they look when they fall on your sleeve.
MENAKA WILHELM: Even though we don't totally understand all the reasons that snowflakes take on these different shapes, we do understand the answer to the next question a little better. It was sent to us by Oliver who lives in Thailand.
OLIVER: Hi, I'm Oliver, and I want to know why two snowflakes are never the same.
MENAKA WILHELM: Ken will share the answer with us in just a bit. But first, we must interrupt this very important snowflake discussion for the--
[MUSIC PLAYING]
CHILD: (WHISPERS) Mystery sound.
MENAKA WILHELM: Here it is.
[MYSTERY SOUND]
PT: It sounds like something falling like a bunch of rice.
MENAKA WILHELM: Mm. That's a good guess. And what did you hear, Ruthie?
RUTHIE: I think it sounds like something falling, and I'm trying to think of how it would be like snow. Like maybe it's like someone's like shoveling snow?
MENAKA WILHELM: Oh, I like that guess. I think thinking about things close to snow is-- you're on the right track. Should we listen to it one more time? It's a pretty short sound.
RUTHIE: Yeah.
PT: OK.
[MYSTERY SOUND]
MENAKA WILHELM: All right, Ruthie, did you hear anything new that time?
RUTHIE: Oh, I heard some like leaves. And I'm not sure if they're leaves, but it just sounded sort of like leaves.
MENAKA WILHELM: Mm.
RUTHIE: But I still don't think it's like shoveling snow.
PT: It sounds like to me, like it's digging out something. So maybe like a crusty bit of dirt, or something, or like snow?
MENAKA WILHELM: I think those are great guesses, and we'll be back with the answer after the credits at the end of the show.
[MUSIC PLAYING]
We're working on an episode all about worms, and we want to hear from you. So Ruthie, if you had a pet worm, what would you name it?
RUTHIE: If I had a pet worm, I would name it Wiggles because worms like to wiggle around in the middle of dirt.
MENAKA WILHELM: And how about you, PT?
PT: If I had a pet worm, I'd name it Isaac Newton.
RUTHIE: Why would you name it Isaac Newton?
PT: Because worms like to hang out in apples, and Isaac Newton's famous because an apple fell on his head.
[LAUGHS]
MENAKA WILHELM: I love that answer, and you can send us your answer by heading to brainson.org/contact. While you're there, you can also send us your drawings, mystery sounds, and questions like this one.
CHRISTIAN: My name is Christian from Saint Louis, Missouri. My question is, how do trees make rings inside, and do the rings really show the trees age?
MENAKA WILHELM: You can hear an answer to that question by listening to the Moment of Um podcast. That's our new bite-sized daily podcast. You can find it wherever you listen to Brains On.
PT: Just search for Moment of Um.
MENAKA WILHELM: And if you're looking for a way to support Brains On, it would mean a lot to us if you would preorder our book. Marc, Molly, and Sanden are sharing their adventures in the Explorerer in the new Brains On book, Road Trip Earth. It's full of comics, photos, and cool facts about our favorite planet Earth.
RUTHIE: You can also preorder the very first Brains On picture book.
PT: It's called Earth Friend Forever.
MENAKA WILHELM: You can preorder them by heading to brainson.org/books.
RUTHIE: Thank you.
PT: And keep listening.
RUTHIE: You're listening to Brains On from APM Studios. I'm Ruthie.
PT: I'm PT.
MENAKA WILHELM: And I'm Menaka. Now, back to this question from Oliver.
OLIVER: I want to know why two snowflakes are never the same.
RUTHIE: Snow expert Ken Libbrecht has an answer.
KEN LIBBRECHT: Well, you start with this little, tiny droplet of ice, and there's a lot of factors that are going into it. When they grow in the clouds, the way they look depends on the path they take through the clouds. So since no two snowflakes follow exactly the same path, no two snowflakes really look exactly alike.
MENAKA WILHELM: The paths are individual and a lot depends on the conditions, too. So temperature, humidity, things like that.
RUTHIE: So as the snowflake moves around, bumping into the water molecules, the shape changes. The crystals form, making a complicated looking and delicate structure.
PT: We have a link to Ken's research in the show notes so you can see the gorgeous photos of snowflakes he's captured.
MENAKA WILHELM: Ken is based in Southern California where it doesn't really snow, so he makes his own snowflakes in the lab. And here's how he does it.
KEN LIBBRECHT: Get a freezer, something cold, and just some water. And I'll heat the water up, and water vapor will come off and then cool down the water vapor. And it automatically starts to grow with ice. And so it's really just a question of controlling that process.
MENAKA WILHELM: If you head to our website, you can get ideas for some cool snowflake related activities you can do even if you don't live in a cold climate. You can preserve snowflakes in glue, make ice spikes in your freezer, or cut some scientifically accurate paper snowflakes. Find the link at our website brainson.org.
ROBOT: Brains, brains, brains on.
MENAKA WILHELM: So Ruthie, you also had some questions about how we make snow. Isn't that right?
RUTHIE: Yes, I wanted to know if you can make snow in hot places like near the equator.
MENAKA WILHELM: That's a great question. And we asked our pal, Ruby Guthrie, to look into this for us.
RUBY GUTHRIE: Hey. Yeah, so turns out, we can make our own snow, even in large amounts with the help of some special equipment. It's called artificial snow. And it turns out in order to make this snow, you need cold air. So it's possible you can make snow up on a mountain near the equator if it were chilly willy. But it wouldn't be cold enough in most places.
RUTHIE: Oh, so I won't be able to have a snowball fight on a tropical beach.
RUBY GUTHRIE: Unfortunately, no. But a sandball fight could be kind of fun. Anyways, your question really got me interested in human made snow. So I visited a place that makes snow here in Minnesota.
MENAKA WILHELM: Wait, Ruby, I'm confused. It's winter, and Minnesota is very cold. Isn't there already a ton of snow there?
RUBY GUTHRIE: Yes, Menaka, you are correct. I do live in Minnesota, and I have to shovel a lot.
RUTHIE: Minnesota, more like Minne-snow-ta. Am I right?
RUBY GUTHRIE: Oh, that was punderful, Ruthie. But yes, you heard right. Even here in Minnesnowta, people still make artificial snow. I wanted to see for myself. So I bundled up and visited my local ski hill.
DAMON JOHNSON: Hello, I'm Damon Johnson. I'm the Maintenance Supervisor here at Hyland Hills Ski Area.
MENAKA WILHELM: Damon is one of the many people who helps make snow here. They're called snow makers. And like most ski hills, Hyland relies on artificial snow for all of their activities.
DAMON JOHNSON: So across this entire hill, we have approximately four feet of snow on average. We have to make all the snow that's out here. We can't really depend on mother nature.
MENAKA WILHELM: Right because sometimes, it doesn't snow, and the ski hill gets dry. Or there's already some natural snow, but not enough to coat the hills for skiing, especially after they use machines like snow plows to even everything out. Now, the artificial snow that Damon makes is a little bit different than the natural snow we're very familiar with.
DAMON JOHNSON: The snow that we make is a little bit different than the snow that comes from the sky. The snow that comes from the sky is more of a flatter flake. It compacts. Here, you get a foot of snow naturally occurring. By the time we would run our machines and equipment through it, you'd probably only end up with a couple of inches of snow. So we rely on our snow makers to do the majority of the snow making here.
RUBY GUTHRIE: That sounds so cool. So how do the snow makers do it? I'm picturing like a giant machine that catapults snowmen into the hills.
[CATAPULT CHAINS]
[PLOPS]
PT: Oh, or a laser ray, but instead of lasers, it's snowflakes.
[LASER RAY SHOT]
RUBY GUTHRIE: Whoa, OK, those sound totally awesome. But that's not quite it. Although, I will say the real machines do remind me of something out of a sci-fi movie, they're called snow cannons or snow guns. Picture this, a big barrel propped up on wheels, about 8 feet tall. One end has a giant fan. And the other end is lined with a halo of tiny nozzles just like the ones on a garden hose. It kind of looks like a jet engine. And turns out, it totally sounds like one, too.
[MACHINE WHIRRING]
Yeah, so that's the sound of a snow gun. And this one is named Kevin to be exact.
RUTHIE: Wait, the snow machine is named Kevin?
RUBY GUTHRIE: Yeah, Kevin the Snow Maker.
MENAKA WILHELM: So how does Kevin work?
RUBY GUTHRIE: Well, you can think of Kevin like a sprinkler on a giant fan, basically, just spraying water high up into the air.
DAMON JOHNSON: The water molecule goes into the air. It kind of freezes. There's like a shell around it almost like an egg, and then you want to get that egg to be frozen by the time it hits the ground.
RUBY GUTHRIE: And these water droplets freeze from the outside in, which creates these little rounded balls of ice, which is a bit different than the natural flakes we talked about earlier. But this artificial snow is actually much better for skiing and snowboarding. It's more compact, which makes it easier to smooth out and groom over the hills. Plus, it melts slower.
PT: So when's the best time to make snow?
DAMON JOHNSON: The best time to make snow is when the air is cold and dry.
RUBY GUTHRIE: And since the air is typically coolest at night, that's when the snow makers get down to business.
[MUSIC PLAYING]
So first, it starts with water. Damon pumps water from a nearby pond, and it's really important that that water is nice and cold. That way, it can freeze faster when it hits the air. But the water needs to be broken up into smaller particles. The solution? Mixing the water with a bit of compressed air. That's when lots of air is stuffed into a small space and builds up pressure, just like in a can of hairspray.
DAMON JOHNSON: It forces the water in the air together and atomizes it into smaller particles and then throws it into the air. And then when it's in the air, we throw it up as high up as we can get it to go, gives it a longer chance to freeze. And then it falls down and lands on the ground.
RUBY GUTHRIE: So the mix of water and pressurized air comes shooting out of the nozzles, and that's when the fan blows everything high, high up. And the higher, the better because the water particles will have a longer chance to freeze as they fall to the ground. What does it look like when you have them all going at once?
DAMON JOHNSON: It's kind of neat. It basically is a big like a snow plume that flies up into the air. When it lands on the ground and starts forming onto the ground, we call those whales because it kind of looks like a whale coming out of the ocean.
RUBY GUTHRIE: That's cool, snow whales, pretty awesome. And then they'll take small snow plows and even out those whales into nice smooth hills, perfect for skiing and snowboarding. And snow whales aside, this can be a tough job. You have to be ready for anything, changes in the wind, machines freezing over, or even water lines breaking. And that can get really messy.
DAMON JOHNSON: And sometimes, if it's really cold after you would get hit with the water, it'll freeze to you instantly. And so you end up being like-- the guys will have jackets that are basically a turtle shell of ice, and when you go inside for break, you just take the jacket off and leave it outside. And then when you go back outside, you put it back on because you already have this protective layer.
RUBY GUTHRIE: Right, it's like armor almost at that point.
DAMON JOHNSON: Yep.
RUBY GUTHRIE: This might be challenging work, but ski hills all over the world from Minnesota to the Winter Olympics really depend on this artificial snow.
MENAKA WILHELM: Thanks for visiting, Ruby.
RUBY GUTHRIE: Any time. Now, I'm off to have a snowball fight with Gungador. This should be good.
RUTHIE: Bye, Ruby.
PT: Bye, hope you don't get crushed.
RUBY GUTHRIE: I'll try my best!
[MUSIC PLAYING]
PT: Snowflakes start as frozen water droplets.
RUTHIE: It collects water vapor up in the clouds, which forms an ice crystal.
PT: Each snowflake is different because they're shaped by the different paths they take.
RUTHIE: It is possible to make artificial snow, but the flakes aren't snow crystals. And you still need cold air.
MENAKA WILHELM: That's it for this episode of Brains On.
RUTHIE: It was produced by Molly Bloom, Ruby Guthrie, Marc Sanchez, Sanden Totten, and Menaka Wilhelm.
MENAKA WILHELM: Our fellow is Anna Goldfield, and our Executive Producer is Beth Pearlman. The executives in charge of APM Studios are Joanne Griffith and Alex Schaffert. Special thanks to Tom Nicely, Luke Davies, and Jessie Litton.
PT: Brains On is a nonprofit public radio program.
MENAKA WILHELM: There are lots of ways you can support the show. You can donate, buy our books, or tell your friends about us.
RUTHIE: Head to brainson.org to find the links, to donate, and to preorder the books.
[MUSIC PLAYING]
MENAKA WILHELM: Now, before we go, let's go back to that mystery sound. Here it is.
[MYSTERY SOUND]
All right, so Ruthie, what's your guess this time?
RUTHIE: So my guess before was someone shoveling snow with maybe leaves in it, and now, I'm hearing something like skiing if somebody is like skiing or getting skis on.
PT: It sounds like snow's like flying through the air. So it could be like a cannon blasting out snow or somebody throwing a snowball.
MENAKA WILHELM: Wow, you guys are right on. Are you ready for the answer?
PT: OK.
RUTHIE: Yes, I'm so ready.
MENAKA WILHELM: So this chilly sound was sent in by Elena from Corbin, Kentucky. And it's what you might hear if you jump on a trampoline full of snow. So PT, you had the snow flying through the air, and Ruthie, you had the sort of like feet crunching through snow part.
RUTHIE: Mm.
PT: Oh, cool.
MENAKA WILHELM: You guys just needed to put your answers together.
RUTHIE: Yeah, I've actually jumped on my friend's trampoline with snow on it, so I should have been able to guess that answer.
PT: I haven't gone on a trampoline with snow, but I've gone on it with water. Sounds like a giant drum.
MENAKA WILHELM: Mm, I've only ever jumped on a trampoline in dry conditions. But Ruthie, when you jumped on a trampoline with snow on it, what did it feel like?
RUTHIE: Well, it felt really weird because the trampoline got slippery, and it was like crunchy because it's sort of like all the snow got balls. And it was just coming down, too. So it felt like it was like an echo of us jumping on it. I was jumping on it, and the snow came down after. So it's really cool.
MENAKA WILHELM: Yeah, so great guesses. You guys both did really great listening there.
PT: Thanks.
MENAKA WILHELM: If you have a mystery sound you want to share with us, you can do that at brainson.org/contact. Everyone who sends a question, an idea, a mystery sound, a drawing, or a high five gets added to the Brains Honor Roll. And here's the most recent group of listeners to be added.
[MUSIC PLAYING]
[LISTING HONOR ROLL]
ROBOTS: (SINGING) Brains Honor Roll, high five.
RUTHIE: We'll be back soon with more answers to your questions.
PT: Thanks for listening!
Transcription services provided by 3Play Media.
